Photodetection device and sensor package

ABSTRACT

A photodetection device of the present invention includes a semiconductor substrate which is defined such that a first light-receiving portion and a second light-receiving portion are spaced from one another, and an optical filter which is formed on the semiconductor substrate, and includes a first filter which is disposed so as to cover the first light-receiving portion, to selectively allow an optic element in a first wavelength band to transmit through, and a second filter which is disposed so as to cover the second light-receiving portion, to selectively allow an optic element in a second wavelength band different from the first wavelength band, to transmit through, and the optical filter has a filter laminated structure which is defined such that edge portions of the first filter and the second filter overlap one another on a boundary region between the first light-receiving portion and the second light-receiving portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application corresponds to Japanese Patent Application No.2013-193272, which is filed in the Japan Patent Office on Sep. 18, 2013,and the entire disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a photodetection device and a sensorpackage having the same.

BACKGROUND ART

For example, Patent Document 1 (Japanese Patent Application PublicationNo. 2009-4680) has disclosed a solid-state imaging apparatus whichincludes an n-type semiconductor substrate, a p-type semiconductor layerwhich is laminated on the n-type semiconductor substrate, an interlayerinsulating film which is laminated on the p-type semiconductor layer,multilayer interference filters which are laminated in sequence on theinterlayer insulating film, and a flattened film, and a plurality ofphotodiodes which are defined in a state of being spaced from oneanother downward in a thickness direction of the p-type semiconductorlayer from the boundary between the p-type semiconductor layer and theinterlayer insulating film. The multilayer interference filters differin thickness so as to correspond to the respective photodiodes, and arespecified in transmissive band at each region so as to correspond to thephotodiodes.

BRIEF SUMMARY OF THE INVENTION

In an apparatus having an arrangement in which a plurality ofphotodiodes are adjacent to one another as in Patent Document 1, in somecases, an optic element obliquely transmitting through a filtercorresponding to one of the photodiodes is incident into the otherphotodiode across the boundary region with another photodiode.

Although it may not be problematic that the incident optic element iswithin a wavelength band which may be detected by the other photodiode,in the case where the optic element is an element in a differentwavelength band, this is a noise component for the other photodiode.

Then, conventionally, in order to prevent a noise component from beingincident into the other photodiode, one of the photodiodes is arrangedfar away from the other photodiode. However, due to this countermeasure,the interval between the adjacent photodiodes is restricted, which hasmade it difficult to downsize the entire layout region for thephotodiodes.

An object of the present invention is to provide a photodetection devicein which it is possible to increase the degree of freedom of an intervalbetween adjacent light-receiving portions, which makes it possible tolessen the entire light-receiving region, and a sensor package havingthe photodetection device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a sensor package according to apreferred embodiment of the present invention.

FIG. 2 is a plan view of a color sensor chip of FIG. 1.

FIG. 3 is a cross-sectional view of the color sensor chip cut alongsection line III-III of FIG. 2.

FIG. 4A is a cross-sectional view of a main portion of the color sensorchip according to a reference example for explanation of an effect ofthe present invention.

FIG. 4B is an enlarged view of a main portion of the color sensor chipof FIG. 3 for explanation of the effect of the present invention.

FIG. 5 is a graph showing the spectroscopic characteristics of an opticelement after transmitting through a blue filter and a red filter.

FIG. 6 is a diagram showing a modified example of the color sensor chipshown in FIG. 3.

FIG. 7 is a diagram showing another modified example of the color sensorchip shown in FIG. 3.

FIG. 8 is an external view of a smartphone according to a preferredembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A photodetection device of the present invention includes asemiconductor substrate having a first light-receiving portion and asecond light-receiving portion, and an optical filter formed on thesemiconductor substrate, the optical filter including a first filtercovering the first light-receiving portion and a second filter coveringthe second light-receiving portion, the first filter is permeableallowing an optic element within a first wavelength band to pass throughthe same, the second filter is permeable allowing an optic elementwithin a second wavelength band different from the first wavelengthband, to pass through the same, and the optical filter has a filterlaminated structure which is defined such that edge portions of thefirst filter and the second filter overlap one another on a boundaryregion between the first light-receiving portion and the secondlight-receiving portion.

In accordance with this arrangement, it is possible to extend the edgeportions of the first filter and the second filter respectively up tothe vicinities of the first light-receiving portion and the secondlight-receiving portion by defining the filter laminated structure.Thereby, it is possible to secure a distance from the firstlight-receiving portion to the peripheral edge of a region through whichthe optic element in the second wavelength band is not allowed totransmit (the region covered by the first filter), broader than thearrangement in which the first filter and the second filter are adjacentto one another in a cross direction (a direction along the top surfaceof the semiconductor substrate) on the boundary region. In the same wayreversely, it is possible to secure a distance from the secondlight-receiving portion to the peripheral edge of a region through whichthe optic element in the first wavelength band is not allowed totransmit (the region covered by the second filter), broad. Therefore,even when the interval between the first light-receiving portion and thesecond light-receiving portion which are adjacent to one another isrelatively narrowed, it is possible to cut a noise component by any oneof the first filter and the second filter which is a part of the filterlaminated structure. Therefore, it is possible to downsize the entirelight-receiving region by shortening a pitch between the firstlight-receiving portion and the second light-receiving portion whilepreventing a false detection of a noise component. Thereby, it ispossible to provide a compact photodetection device.

The edge portions of the first filter and the second filter may berespectively extended up to a side closer to the second light-receivingportion and the first light-receiving portion than a center of theboundary region.

In accordance with this arrangement, it is possible to obtain a distancefrom the first light-receiving portion to the peripheral edge of aregion through which the optic element in the second wavelength band isnot allowed to transmit as an amount across the center of the boundaryregion. In the same way reversely, it is possible to obtain a distancefrom the second light-receiving portion to the peripheral edge of aregion through which the optic element in the first wavelength band isnot allowed to transmit as an amount across the center of the boundaryregion. Thereby, it is possible to satisfactorily cut a noise componentwhose incident angle is relatively small with respect to each of thefirst light-receiving portion and the second light-receiving portion.

The photodetection device may further include a metal layer formed alonga top surface of the semiconductor substrate between the filterlaminated structure and the boundary region.

In accordance with this arrangement, even when a noise componenttransmits laterally through the filter laminated structure, to headtoward the first light-receiving portion and the second light-receivingportion, it is possible to repeatedly reflect the noise componentbetween the metal layer and the filter laminated structure, to beattenuated. Therefore, even when the noise component is detected by thefirst light-receiving portion and the second light-receiving portion, aneffect on the detection accuracy may be sufficiently small.

The metal layer may overlap edge portions of the first light-receivingportion and/or the second light-receiving portion.

In accordance with this arrangement, it is possible to reliably preventa noise component from being directly incident into the firstlight-receiving portion and the second light-receiving portion. That is,it is possible to reliably reflect the noise component between the metallayer and the filter laminated structure.

The photodetection device may further include a plurality of interlayerinsulating films and a passivation film which are laminated in sequencefrom the semiconductor substrate between the semiconductor substrate andthe optical filter, and the metal layer is disposed on an interlayerinsulating film lower than an uppermost insulating film among theplurality of interlayer insulating films.

In accordance with this arrangement, because it is possible to flattenthe top surface of the passivation film at least in a region covered bythe optical filter, it is possible to reduce harmful effects on thecharacteristics of the optical filter on the passivation film.

The photodetection device may further include an uppermost wiring whichis formed on the uppermost insulating film outside of a region coveredby the optical filter, and is covered with the passivation film.

In accordance with this arrangement, because the passivation film is notnecessarily flat in the region outside of the region covered by theoptical filter, it is possible to effectively utilize this region as aspace for defining the wiring.

The metal layer may be made of aluminum.

In accordance with this arrangement, in the case where an aluminumwiring is formed on the interlayer insulating film, it is possible toform the metal layer in the same process as the aluminum wiring.

The photodetection device may further include a p-n junction portionformed on a top surface portion of the semiconductor substrate under themetal layer.

In accordance with this arrangement, even when it is impossible toreflect a noise component transmitting laterally through the filterlaminated structure by the metal layer, it is possible to absorb thenoise component with the p-n junction portion.

The photodetection device may further include a p-n junction portionformed on the top surface portion of the semiconductor substrate betweenthe filter laminated structure and the boundary region.

In accordance with this arrangement, even when a noise componenttransmits laterally through the filter laminated structure, to headtoward the first light-receiving portion and the second light-receivingportion, it is possible to absorb the noise component with the p-njunction portion.

The filter laminated structure may be defined such that the first filterand the second filter overlap one another several times.

In accordance with this arrangement, it is possible to more effectivelycut a noise component in the filter laminated structure.

The optical filter may include a color filter.

In accordance with this arrangement, it is possible to suppress colormixture caused by a noise component.

A width of the boundary region may be 5 μm to 25 μm.

In accordance with this arrangement, it is possible to provide a compactphotodetection device with a width of the boundary region of 5 μm to 25μm.

A sensor package of the present invention includes the photodetectiondevice.

In accordance with this arrangement, because the photodetection deviceof the present invention which can be downsized is included, it ispossible to provide a compact sensor package.

Hereinafter, a preferred embodiment of the present invention will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a sensor package 1 according to apreferred embodiment of the present invention.

The sensor package 1 includes a package main body 2, a color sensor chip3, and an infrared filter 4.

The package main body 2 is made of, for example, a cubic box-shapedlight blocking resin having an upper open portion in its top surface.The color sensor chip 3 is provided in a space 5 of the package mainbody 2. A plurality of leads 6 are provided so as to stride across theinterior and exterior of the space 5, to penetrate through the sidewalls of the package main body 2.

The color sensor chip 3 is installed in a posture of setting itslight-receiving surface 7 upward in the space 5 of the package main body2. For example, the color sensor chip 3 is die-bonded on a die-pad (notshown) integrally formed with some of the plurality of leads 6. Aplurality of electrode pads 8 are formed on the light-receiving surface(top surface) 7 of the color sensor chip 3. The electrode pads 8 and theleads 6 are connected in one-on-one with bonding wires 9.

The infrared filter 4 is disposed so as to close the upper open portionof the package main body 2, and selectively cuts (absorbs) an element ina wavelength band (for example, 700 nm to 1300 nm) of an infrared ray oflight toward the space 5 in the package main body 2. With the infraredfilter 4, it is possible to supply the light from which the opticelement in the infrared wavelength band is cut to the color sensor chip3.

Next, a detailed arrangement of the color sensor chip 3 will bedescribed with reference to FIGS. 2 and 3.

FIG. 2 is a plan view of the color sensor chip 3 of FIG. 1. FIG. 3 is across-sectional view of the color sensor chip 3 cut along section lineIII-III of FIG. 2.

The color sensor chip 3 is an RGB sensor which is capable of detectingoptic elements in a wavelength band of a visible ray (basically, itsshort-wavelength limit is 360 nm to 400 nm, and its long-wavelengthlimit is 760 nm to 830 nm) so as to divide the respective color signalsof red (R), green (G), and blue (B).

The color sensor chip 3 includes a semiconductor substrate 10, and acolor filer 11.

The semiconductor substrate 10 is, in the present preferred embodiment,an n-type silicon substrate. The semiconductor substrate 10 is definedas a rectangular shape in a plan view, and a light-receiving region 12is set in its central portion, and an outer peripheral region 13 is setat the peripheral edge portion surrounding the light-receiving region12.

A plurality of photodiodes 14R, 14G, and 14B and a dummy photodiode 15are formed on the top surface portion of the semiconductor substrate 10in the light-receiving region 12.

The plurality of photodiodes 14R, 14G, and 14B respectively andselectively detect an element in a red wavelength band (for example, 590nm to 680 nm), an element in a green wavelength band (for example, 500nm to 560 nm), and an element in a blue wavelength band (for example,420 nm to 480 nm) among visible rays incident into the color sensor chip3. The plurality of photodiodes 14R, 14G, and 14B are arranged fromp-type semiconductor regions 16R, 16G, and 16B which are arrayed atgiven intervals from one another and the p-n junctions with the n-typesemiconductor substrate 10.

The array mode of the plurality of p-type semiconductor regions 16R,16G, and 16B is a square-lattice array in the present preferredembodiment. In this array mode, for example, as shown in FIG. 2, the twoof the p-type semiconductor region 16R and the p-type semiconductorregion 16B may be disposed opposite to one another, and the p-typesemiconductor region 16B and the p-type semiconductor region 16G may bediagonally disposed opposite to one another. Thereby, an n-type boundaryregion 17 defined such that the regions among the photodiodes 14R, 14G,and 14B which are adjacent to one another are connected in a cross shapein a plan view is formed on the top surface portion of the semiconductorsubstrate 10. In addition, the array mode of the p-type semiconductorregions 16R, 16G, and 16B is not limited to a square-lattice array, andmay be, for example, a honeycomb array or the like, and the positions ofthe p-type semiconductor regions 16R, 16G, and 16B in the respectivearray modes may be appropriately set.

A width W₁ of the n-type boundary region 17 (an interval between thep-type semiconductor regions 16R, 16G, and 16B adjacent to one another)is, for example, 5 μm to 25 μm. The dummy photodiode 15 is defined by ap-n junction between a p-type semiconductor region 18 formed in then-type boundary region 17 and the n-type semiconductor substrate 10.

The p-type semiconductor region 18 is defined as a cross shape along thelines of the planar shape of the n-type boundary region 17, and theentire p-type semiconductor region 18 is housed in the n-type boundaryregion 17 so as not to protrude from the n-type boundary region 17 tothe outside. Further, the p-type semiconductor region 18 is defined atintervals from the p-type semiconductor regions 16R, 16G, and 16B byinterposing n-type portions on the both sides among the p-typesemiconductor regions 16R, 16G, and 16B adjacent to one another.Moreover, in the present preferred embodiment, the p-type semiconductorregions 16R, 16G, and 16B and the p-type semiconductor region 18respectively have depths which are the same as each other. Thereby, itis possible to simultaneously form the p-type semiconductor regions 16R,16G, and 16B and the p-type semiconductor region 18 by selectivelyinjecting and diffusing p-type dopant with respect to the top surface ofthe n-type semiconductor substrate 10.

The color filter 11 includes a red filter 19R, a green filter 19G, and ablue filter 19B. As the color filter 11, for example, a color resistfilm based on pigment, a transparent type resist film formed by use of ananoimprint technology, a gelatin film, or the like may be used. Inaddition, in FIG. 2, in order to clearly delineate, the red filter 19R,the green filter 19G, and the blue filter 19B are respectively expressedby areas added by broken line hatching, dashed-dotted line hatching, andsolid line hatching. Further, in FIG. 3, the red filter 19R and the bluefilter 19B which are adjacent to one another among the red filter 19R,the green filter 19G, and the blue filter 19B are respectively shown asexamples of the first filter and the second filter of the presentinvention.

The red filter 19R, the green filter 19G, and the blue filter 19B arerespectively disposed immediately above the photodiodes 14R, 14G, and14B, and integrally include main portions 20R, 20G, and 20B facing therespective photodiodes 14R, 14G, and 14B in a vertical direction(up-and-down direction), and peripheral edge portions 21R, 21G, and 21Bwhich are led out of the respective main portions 20R, 20G, and 20B in ahorizontal direction (cross direction).

The respective peripheral edge portions 21R, 21G, and 21B arerespectively defined as a ring shape so as to surround the peripheriesof the respective main portions 20R, 20G, and 20B in the presentpreferred embodiment. Further, the lead-out amounts from the respectivemain portions 20R, 20G, and 20B of the respective peripheral edgeportions 21R, 21G, and 21B (the distances from the peripheral edges ofthe respective photodiodes 14R, 14G, and 14B up to the peripheral edgesof the peripheral edge portions 21R, 21G, and 21B) are set to amountsover the half of the width W₁ of the n-type boundary region 17. Forexample, as shown in FIG. 3, the peripheral edge portions 21R and 21Bare respectively extended so as to protrude toward the side closer tothe photodiodes 14B and 14R than the central portion C in the widthdirection of the n-type boundary region 17. Thereby, making therespective lead-out amounts W₂ and W₃ of the peripheral edge portions21R and 21B greater than the half of the width W₁ of the n-type boundaryregion 17.

In the present preferred embodiment, as described above, because therespective peripheral edge portions 21R, 21G, and 21B are formed so asto extend across the central portion C of the n-type boundary region 17,the adjacent peripheral edge portions 21R, 21G, and 21B overlap oneanother on the n-type boundary region 17. For example, in FIG. 2, thehatchings showing the respective filters 19R, 19G, and 19B are madecrossover, thereby expressing the overlapping portion. Thereby, defininga filter laminated structure 22 by the overlapping of the peripheraledge portions 21R, 21G, and 21B in the color filter 11.

The filter laminated structure 22 is defined such that the peripheraledge portions 21R, 21G, and 21B of the respective filters 19R, 19G, and19B overlap one another several times in the color sensor chip 3. Forexample, as shown in FIG. 3, the red filter 19R and the blue filter 19Bare respectively arranged such that two color resist films arelaminated. Then, at the portion of the filter laminated structure 22,the respective color resist films of the red filter 19R and the bluefilter 19B are alternately laminated. In detail, the filter laminatedstructure 22 is arranged such that the downside film of the red filter19R, the downside film of the blue filter 19B, the upside film of thered filter 19R, and the upside film of the blue filter 19B are laminatedin sequence.

Such a filter laminated structure 22 may be defined such that, forexample, a resist film of the red filter 19 is defined as apredetermined pattern on the top surface of a passivation film 25 whichwill be described later, and a resist film of the blue filter 19B isformed on this resist film as a pattern so as to overlap a part thereofwith the red filter 19R. In the case where the films overlap severaltimes as in FIG. 3, this process may be repeated several times.

As shown in FIG. 3, the color sensor chip 3 further includes a pluralityof interlayer insulating films 23 and 24 and the passivation film 25which are laminated in sequence from the semiconductor substrate 10between the semiconductor substrate 10 and the color filter 11, andwiring layers 26 and 27 which are disposed on the plurality ofinterlayer insulating films 23 and 24. That is, the color sensor chip 3has a multilayer wiring structure on the semiconductor substrate 10.

In the present preferred embodiment, the interlayer insulating films 23and 24 are made of silicon oxide (SiO₂), the passivation film 25 is madeof silicon nitride (SiN), and the wiring layers 26 and 27 are made ofaluminum. In addition, the plurality of interlayer insulating films maybe two layers as in FIG. 3, and may be more than two layers.

The interlayer insulating film 24 is an uppermost insulating film. Thetop surface of the light-receiving region 12 in this uppermostinsulating film 24 is a flat surface on which no wiring layer is formed.On the other hand, a wiring layer 27 is formed on the uppermostinsulating film 24 in the outer peripheral region 13. The wiring layer27 exposes its parts as the electrode pads 8 from the passivation film25.

The wiring layer 26 is disposed on the interlayer insulating film 23lower than the uppermost insulating film 24 in the light-receivingregion 12. In this way, the wiring layer 26 disposed in thelight-receiving region 12 is formed on the interlayer insulating film 23lower than the uppermost insulating film 24, thereby it is possible toflatten the interface between the passivation film 25 and the uppermostinsulating film 24. In other words, when a wiring layer is formed in thelight-receiving region 12 of the uppermost insulating film 24, thepassivation film 25 is raised at the region in which the wiring layer isformed, and the raised region might cause a negative effect on thecharacteristics of the color filter 11. However, it is possible toreduce such a negative effect.

Further, the wiring layer 26 is formed along the top surface of thesemiconductor substrate 10 so as to stride across the photodiode 14R andthe photodiode 14B. In detail, the wiring layer 26 is defined as a crossshape along the lines of the planar shape of the p-type semiconductorregion 18, and is housed in the n-type boundary region 17 so as not toprotrude from the n-type boundary region 17 to the outside in alongitudinal direction (the straight line direction of the cross in thepresent preferred embodiment) of the n-type boundary region 17. On theother hand, the wiring layer 26 is formed so as to protrude (be led out)to the outside from the n-type boundary region 17 in a width directionof the n-type boundary region 17 perpendicular to the longitudinaldirection, and overlaps the edge portions of the photodiode 14R and thephotodiode 14B. That is, the wiring layer 26 has a lead-out portionwhich is led out to the internal regions of the p-type semiconductorregion 16R and the p-type semiconductor region 16B with respect to therespect peripheral edges of the p-type semiconductor region 16R and thep-type semiconductor region 16B compartmenting the n-type boundaryregion 17.

The passivation film 25 is formed so as to cover the light-receivingregion 12 and the outer peripheral region 13 of the uppermost insulatingfilm 24. Pad openings 28 which are for exposing the wiring layer 27 asthe electrode pads 8 are formed in the outer peripheral region 13 of thepassivation film 25. The passivation film 25 is raised at a region inwhich the wiring layer 27 is formed. However, the outer peripheralregion 13 in which this raised region is formed is a region in which thecolor filter 11 is not substantially formed as in FIG. 3, and even ifthe color filter 11 is formed, there is no photodiodes 14R and 14Bimmediately beneath it. Accordingly, even if the passivation film 25 isnot flat, this hardly causes a negative effect on the characteristics ofthe color filter 11. Therefore, in the present preferred embodiment, itis possible to effectively utilize the outer peripheral region 13 as aspace for defining the wiring layer 27 (the electrode pads 8).

Further, the color sensor chip 3 includes a cathode electrode 29 formedon the rear surface of the semiconductor substrate 10. The cathodeelectrode 29 is bonded to the entire rear surface of the semiconductorsubstrate 10, to be a cathode terminal common for the plurality ofphotodiodes 14R, 14G, and 14B, and the dummy photodiode 15. Further, thecathode electrode 29 is bonded to, for example, a die pad (not shown) inthe package main body 2 (FIG. 1) via a bonding material such as a solderat the time of packaging the color sensor chip 3. On the other hand,although not shown, anode terminals are respectively providedindividually to the plurality of photodiodes 14R, 14G, and 14B, and thedummy photodiode 15, and are respectively electrically connected to theelectrode pads 8 on the outer peripheral region 13.

Next, the effects obtained by the color sensor chip 3 will be describedwith reference to FIGS. 4A and 4B, and FIG. 5.

FIG. 4A is a cross-sectional view of a main portion of a color sensorchip 30 according to a reference example for explanation of an effect ofthe present invention. FIG. 4B is an enlarged view of a main portion ofthe color sensor chip 3 of FIG. 3 for explanation of the effect of thepresent invention. FIG. 5 is a graph showing the spectroscopiccharacteristics of an optic element after transmitting through a bluefilter and a red filter.

First, the arrangement of the color sensor chip 30 according to thereference example will be described. In addition, in FIG. 4A, portionscorresponding to the respective portions shown in FIG. 3 described aboveare shown by adding the same reference numerals thereto.

The color sensor chip 30 includes a color filter 31 including a redfilter 31R and a blue filter 31B in place of the color filter 11described above. The red filter 31R and the blue filter 31B are adjacentto one another at a minute interval in a horizontal direction so as tointerpose the central portion C therebetween on the n-type boundaryregion 17.

However, the arrangement in which the red filter 31R and the blue filter31B are adjacent to one another restricts, for example, a distance W₄from the photodiode 14R to the peripheral edge of a region through whichan optic element in a blue wavelength band is not allowed to transmit (aregion covered by the red filter 31R) to the half or less of the widthW₁ of the n-type boundary region 17. Therefore, it is impossible tosecure a distance up to a region where the blue optic element flows out,broad. Therefore, as shown by an arrow BL₁ in FIG. 4A, an optic elementwhich transmits through the blue filter 31B to be obliquely incidentinto the vicinity of the n-type boundary region 17 might be incidentinto the photodiode 14R. In addition, because the dummy photodiode 15and the wiring layer 26 are not formed in the color sensor chip 30,there are no other means for cutting the blue optic element otherwise.As a result, in some cases, the blue optic element may be detected as anoise component by the photodiode 14R. Accordingly, in order to preventa noise component from being detected in the arrangement of the colorsensor chip 30, it is necessary to make the interval W₁ between theadjacent photodiode 14R and photodiode 14B as broad as possible.

In contrast thereto, in the color sensor chip 3 in the present preferredembodiment, as shown in FIG. 4B, the filter laminated structure 22 isdefined such that the red filter 19R and the blue filter 19B overlap oneanother, thereby, it is possible to extend the peripheral edge portion21R and the peripheral edge portion 21B respectively up to thevicinities of the photodiode 14B and the photodiode 14R across thecentral portion C of the n-type boundary region 17. Thereby, it ispossible to secure a distance W₂ from the photodiode 14R to a regionthrough which the optic element in the blue wavelength band is notallowed to transmit (the region covered by the red filter 19R), broaderthan the distance W₄ in FIG. 4A. Therefore, even if the interval W₁between the photodiode 14R and the photodiode 14B is relativelynarrowed, it is possible to cut the blue optic element shown by an arrowBL₂ in FIG. 4B with the red filter 19R which is a part of the filterlaminated structure 22. Therefore, it is possible to downsize the entirelight-receiving region 12 by shortening a pitch between the photodiodes14R and 14B while preventing a false detection of a noise component.Thereby, it is possible to provide the compact color sensor chip 3.

In the color sensor chip 3, the wiring layer 26 is further formed so asto stride across the photodiode 14R and the photodiode 14B immediatelybeneath the filter laminated structure 22. Thereby, even if the blueoptic element (the noise component) transmits laterally through thefilter laminated structure 22, to head toward the photodiode 14R asshown by an arrow BL₃ in FIG. 4B, it is possible to repeatedly reflectthe noise component between the wiring layer 26 and the filter laminatedstructure 22 (see the zig-zag broken line in FIG. 4B), to be attenuated.Accordingly, even when the noise component is detected by the photodiode14R, an effect on the detection accuracy may be sufficiently small.

In addition, in the present preferred embodiment, the wiring layer 26 isformed so as to overlap the edge portions of the photodiode 14R and thephotodiode 14B. Therefore, it is possible to reliably prevent a noisecomponent by an arrow BL₃ from being directly incident into thephotodiode 14R. That is, it is possible to reliably reflect the noisecomponent between the wiring layer 26 and the filter laminated structure22. Further, because the wiring layer 26 is made of aluminum, forexample, in the case where an aluminum wiring is formed on theinterlayer insulating film 23, it is possible to form the wiring layer26 in the same process as the aluminum wiring.

Further, the dummy photodiode 15 having a p-n junction is formed on thetop surface portion of the semiconductor substrate 10 immediatelybeneath the wiring layer 26, that is, in the n-type boundary region 17.Therefore, the p-n junction of the dummy photodiode 15 isinversely-biased, thereby, as shown by an arrow BL₄ in FIG. 4B, evenwhen it is impossible to reflect a noise component transmittinglaterally through the filter laminated structure 22, by the wiring layer26, it is possible to absorb the noise component with the p-n junctionportion of the dummy photodiode 15. In addition, an n-p-n transistor isformed in the n-type boundary region 17, thereby it is possible toobtain the effect which is the same described above by utilizing aparasitic diode of the n-p-n transistor.

The above effect has been described as an example in the case where avisible optic element (a noise component) other than the red wavelengthband heads toward the photodiode 14R. However, it is possible to obtainthe same effect even in the case where an element which may be a noisecomponent for the photodiode heads toward the photodiodes 14G and 14B.That is, in the present preferred embodiment, because the red filter19R, the green filter 19G, and the blue filter 19B define the filterlaminated structure 22 together with the filters adjacent to oneanother, it is possible to obtain the same effect by the filterlaminated structure 22.

Then, it is proved by FIG. 5 that the optic element after transmittingthrough the filter laminated structure 22 including the red filter 19Rand the blue filter 19B does not contain the both elements in the blueand red wavelength bands.

Further, as shown in FIG. 5, it is clear that the transmitted light hasa peak only in an infrared wavelength band (for example, 850 nm to 950nm), and has few or no peaks in a wavelength band of a visible raycontaining the red and blue elements (basically, its short-wavelengthlimit is 360 nm to 400 nm, and its long-wavelength limit is 760 nm to830 nm). From the result of FIG. 5, it is proved that the filterlaminated structure 22 of the present preferred embodiment is capable ofcutting both of the red and blue optic elements. In addition, it ispossible to easily cut an element in the infrared wavelength band inwhich the peak is shown in the graph of FIG. 5 by the infrared filter 4in FIG. 1 or an infrared multilayer film interference filter.

The preferred embodiment of the present invention has been describedabove. However, the present invention may be implemented by anotherpreferred embodiment.

For example, in the color sensor chip 3, as shown in FIG. 6, the filterlaminated structure 22 may be defined such that the peripheral edgeportions 21R and 21B of the respective filters 19R and 19B overlap onlyone time.

Further, in the color sensor chip 3, the peripheral edge portions 21R,21G, and 21B of the respective filters 19R, 19G, and 19B may not beextended across the central portion C of the n-type boundary region 17.For example, as shown in FIG. 7, the peripheral edge portion 21R of thered filter 19R may be disposed on the nearer side (the side close to thephotodiode 14R) than the central portion C of the n-type boundary region17.

Further, in the preferred embodiment of the aforementioned preferredembodiment, an infrared multilayer film interference filter whichselectively cuts an element in an infrared wavelength band of light mayfurther be laminated on the color filter 11. In this case, the infraredfilter 4 may be omitted in the sensor package 1.

Further, in addition to the plurality of photodiodes 14R, 14G, and 14Band the dummy diode 15, various types of circuit elements such as atransistor, a capacitor, and a resister which arrange an integratedcircuit such as an LSI (Large Scale Integration) may be formed on thesemiconductor substrate 10.

Further, the photodetection device of the present invention may beapplied to, not only a color sensor, but also an optical sensor having aplurality of optical filters, such as an illumination sensor or aproximity sensor. Moreover, these optical sensors may be installed in,for example, a smartphone, a mobile telephone, a digital camera, acar-navigation system, a laptop computer, a tablet PC, or the like.

For example, a smartphone 101 according to a preferred embodiment of thepresent invention has an appearance shown in FIG. 8.

The smartphone 101 is arranged so as to house electric parts (forexample, the aforementioned color sensor chips 3 and 30, and the like)inside a flat cubic-shaped casing 102.

The casing 102 has a pair of oblong principal surfaces on the upper sideand the rear side, and the pair of principal surfaces are connected withthe four side surfaces. A display surface of a display panel 103 whichis arranged from a liquid crystal panel, an organic EL panel, and thelike, is exposed to one principal surface of the casing 102. The displaysurface of the display panel 103 arranges a touch-panel, which providesan input interface to a user.

The display panel 103 is defined as a rectangular shape to account for alarge part of the one principal surface of the casing 102. Manualoperation buttons 104 are disposed so as to be along one narrow side ofthe display panel 103. In the present preferred embodiment, theplurality of (three) manual operation buttons 104 are arrayed along thenarrow side of the display panel 103. A user operates the manualoperation buttons 104 and the touch panel, thereby it is possible tooperate the smartphone 101, so as to call a necessary function, toexecute the function.

A speaker 105 is disposed in the vicinity of the other narrow side ofthe display panel 103. The speaker 105 provides an earpiece fortelephone function, and may be used as an acoustic conversion unit forreproducing music data and the like. On the other hand, a microphone 106is disposed in one side surface of the casing 102 in the vicinity of themanual operation buttons 104. The microphone 106 provides a mouthpiecefor telephone function, and may be used as a microphone for soundrecording.

In addition, various types of design changes are applicable within thescope of matters described in the following claims.

What is claimed is:
 1. A photodetection device comprising: asemiconductor substrate having a first light-receiving portion and asecond light-receiving portion; and an optical filter formed on thesemiconductor substrate, the optical filter including a first filtercovering the first light-receiving portion and a second filter coveringthe second light-receiving portion, wherein the first filter ispermeable allowing an optic element within a first wavelength band topass through the same, the second filter is permeable allowing an opticelement within a second wavelength band different from the firstwavelength band, to pass through the same, and the optical filter has afilter laminated structure which is defined such that edge portions ofthe first filter and the second filter overlap one another on a boundaryregion between the first light-receiving portion and the secondlight-receiving portion.
 2. The photodetection device according to claim1, wherein the edge portions of the first filter and the second filterare respectively extended up to a side closer to the secondlight-receiving portion and the first light-receiving portion than acenter of the boundary region.
 3. The photodetection device according toclaim 1 further comprising a metal layer formed along a top surface ofthe semiconductor substrate between the filter laminated structure andthe boundary region.
 4. The photodetection device according to claim 3,wherein the metal layer overlaps edge portions of the firstlight-receiving portion and/or the second light-receiving portion. 5.The photodetection device according to claim 3 further comprising aplurality of interlayer insulating films and a passivation film whichare laminated in sequence from the semiconductor substrate between thesemiconductor substrate and the optical filter, wherein the metal layeris disposed on an interlayer insulating film lower than an uppermostinsulating film among the plurality of interlayer insulating films. 6.The photodetection device according to claim 5 further comprising anuppermost wiring which is formed on the uppermost insulating filmoutside of a region covered by the optical filter, and is covered withthe passivation film.
 7. The photodetection device according to claim 3,wherein the metal layer is made of aluminum.
 8. The photodetectiondevice according to claim 3 further comprising a p-n junction portionformed on a top surface portion of the semiconductor substrate under themetal layer.
 9. The photodetection device according to claim 1 furthercomprising a p-n junction portion formed on the top surface portion ofthe semiconductor substrate between the filter laminated structure andthe boundary region.
 10. The photodetection device according to claim 1,wherein the filter laminated structure is defined such that the firstfilter and the second filter overlap one another several times.
 11. Thephotodetection device according to claim 1, wherein the optical filterincludes a color filter.
 12. The photodetection device according toclaim 1, wherein a width of the boundary region is 5 μm to 25 μm.
 13. Asensor package comprising a photodetection device, wherein thephotodetection device includes a semiconductor substrate having a firstlight-receiving portion and a second light-receiving portion, and anoptical filter formed on the semiconductor substrate, the optical filterincluding a first filter covering the first light-receiving portion anda second filter covering the second light-receiving portion, and thefirst filter is permeable allowing an optic element within a firstwavelength band to pass through the same, the second filter is permeableallowing an optic element within a second wavelength band different fromthe first wavelength band, to pass through the same, and the opticalfilter has a filter laminated structure which is defined such that edgeportions of the first filter and the second filter overlap one anotheron a boundary region between the first light-receiving portion and thesecond light-receiving portion.
 14. An electronic equipment comprising aphotodetection device, wherein the electronic equipment includes asemiconductor substrate having a first light-receiving portion and asecond light-receiving portion, and an optical filter formed on thesemiconductor substrate, the optical filter including a first filtercovering the first light-receiving portion and a second filter coveringthe second light-receiving portion, and the first filter is permeableallowing an optic element within a first wavelength band to pass throughthe same, the second filter is permeable allowing an optic elementwithin a second wavelength band different from the first wavelengthband, to pass through the same, and the optical filter has a filterlaminated structure which is defined such that edge portions of thefirst filter and the second filter overlap one another on a boundaryregion between the first light-receiving portion and the secondlight-receiving portion.